Method of charging blast-furnaces.



' UNITED @TATEti SPATEET ora ion T THOMAS MGDONALID AND, JACOB C. BARRETT, OF YOUNGSTOWN, OHIO.

IS/IE'LIEIQD OF CHARGING BLAST-FURNACES.

No Drawing.

Specification of Letters Patent.

Application filed March 27, 1909. Serial No. 486,229.

Patented Mar. 8, 15910.

To all iii/tom it may concern:

Be it known that we, THOMAS MCDONALD and J ACOB C. BARRETT, both of Youngstown,

1n the county of Mahoning and State of Ohio, have invented a new and useful Method of Charging Blast-Furnaces, of which the following is a full, clear, and exact descripand charging the ores. or other materials forming the burden by the use pf which the yield of iron from the materials charged is largely increased, while the cost of producing the iron is greatly reduced, and in the use of which the proportion of finely divided ore materials in the materials used can be largely increased, while the amount of flue dust carriedfrom the furnaces in the gases is lessened.

A large proportion of the iron ores now available for use is in a finely divided state and when such materials are charged into the blast furnaces a considerable amountof the comminuted materials is carried out of the furnace in suspension in the blast furnace gases into the gas mains, dust catchers and furnace stoves, where it becomes deposited. The deposits of finely divided materials must be removed from the places in which they become deposited, the handling of which adds to the cost of operating the furnaces.

\Ve have discovered that by mixing the charges of materials forming the furnace burden or the charges of the ore or iron bearing materials withcnough water to make the water content equal at leastthree per cent. by weight of the materials and then charging the wetted materials into the furnace, that the proportion of finely divided materials forming the'furnace burden can be largely increased, while the percentage of the materials charged that will he carried out of the furnaces inthe form of flue dust, will be very materially decreased, and that the temperature of the top portion ,of the furnace will be lessened, the coke consumption reduced, and the working of the furnaces be made more uniform.

In the preparation of the materials, preferably only the ores are mixed with water, so

5 as to form a more or less pasty mass which is then charged into the furnace although burden may be wetted if desired. The Wet, pasty mass, when charged into the blast furnaces forms a cover or blanket over the materials previously charged and the finely divided materials located at a lower level in the furnaces, from which the moisture has been expelled by the heat of the furnaces are retained in the furnaces, and their escape with the gases, which pass through the wet pasty materials, is overcome and prevented.

The mixing of the water With the materials is preferably done just as the 7 macar or bucket in which they are hoisted to the materials into the furnace shaft from its lower bell and hopper. Obviously the water may be added and mixed with the materials in a revolving drum or other form of mixing apparatus from which the resulting paste is transferred to the skip car or hoisting bucket. Y

The advantages of our invention are many art. The percentage of materials charged into the furnace which are carried out of the furnace in the form of fine dust is very materially reduced, while the yield of iron per ton of ore charged is greatly increased, in this way resulting in a very considerable reduction in the cost of the smelting operation. The gases passing from the furnaces are cleaner and their heating qualities thereby increased, while the reduction in the amount of flue dust formed and necessary to handle in cleaning the gas mains, dust catchers and stoves tends to lessen the operating cost of the furnace. The burden of the blast furnaces can be formed of a greater proportion of finely divided materials than has heretofore been found possible. Our improved being used in the burden than that formed by the furnace, when found necessary or desirable. The addition of the water to the burden forming materials lessens the temperature in the top of the furnace shaft, in this way preventing warping or cracking of the bell, hopper or hopper extension of the furnace. The amount of water added to the burden may be increased above three per cent, without departing from our invention all of the materials forming the furnace terials are being discharged into the skip' the furnace top, although the Water maybe, i added at any time prior to the discharge of and will be apparent to those skilled in themethod enables a larger amount of flue dust tea.

surest method "which consists in the mixture with cent. by Weight, of water with the successive charges of materials, and then charging the 1 wet materials into the blast turnace; substantially as described. 2. In the charging ot blast furnaces, the

steps consisting in mixing; at least three per cent, by Weight, of Water with the successive charges of ore and then charging the wet; materials into the blast furnace; substantially as described. 5

3. The method of charging blast furnaces, consisting in mixing the ore of the furnace burden with a measured quantity of water and charging the mixture while Wet into the furnace; substantially as described.

4. The method of charging blast furnaces consisting in mixing the materials forming the burden with a dehmte Weight of water and then charging the wet materials into the l furnace; substantially as described.

the ore. of an amount of water in excess of that due to natural causes whereby the amount of" water present charges is-made to equal at least three per cent. by Weight ot' the materials; substantially as (lBSClll' )C(l.

('1. In the m of operating blast furnaces,

the methodconsisting in reiulerintr the :uuount of Water present in successive charges of the burden substantially constant by the addition of an amount of water to the charges sutlicient to give each charge of like material a water content equal to at least three .per cent. by weight of the material; substantially as described:

in testhnrmy whereof, we have hereunto set. our hands.

'lHOBLKS hleDON All D. JACOB C. BA filth) ."l.

Witnesses i WARREN PERRY,

A. C. Coon.

in successive 

